Hitherto, in the structural members for motor vehicles, aircrafts, and the like, Al—Cu-based JIS 2000 series aluminum alloys and Al—Cu—Mg—Zn-based JIS 7000 series aluminum alloys capable of having a high proof stress and a high strength are used (for example, see Patent Literature 1). In order to improve the formability of these aluminum alloys at the time of bending and the like, the aluminum alloy members for structural members are manufactured by conducting hot forming to form the aluminum alloy by decreasing the rigidity while heating it or W forming to form the aluminum alloy by softening it through a heat treatment (solution heat treatment) and then enhancing the strength again through a heat treatment (aging treatment).